Unit 2-Lesson 1 The immune system Flashcards
What is the immune system?
The body’s defense against disease-causing organisms, malfunctioning cells, and foreign particles.
What role does the lymphatic system play in the immune system?
It helps remove toxins from the body, destroys pathogens, and filters waste.
What is immunity?
The condition of being resistant to pathogens and the diseases they cause.
What are pathogens?
Harmful microorganisms that could cause disease.
What is nonspecific (innate) immunity?
Protects the body against everyday foreign invaders through general mechanisms.
Give an example of nonspecific immunity.
- Skin forming a barrier
- Hairs in lungs filtering bacteria
- Stomach acid breaking down food and pathogens
What is specific (adaptive) immunity?
Targets and attacks a specific foreign agent or pathogen.
Name a structure in the immune system.
- Tonsils
- Thymus
- Lymph Nodes
- Spleen
- Appendix
- Peyer’s Patch
- Bone Marrow
What do lymph nodes contain?
Reticular tissue filled with lymphocytes and macrophages.
What is the major function of the lymphatic system?
To pick up extra tissue fluid (lymph), filter it, and return it to the bloodstream.
How does lymph circulate throughout the lymphatic system?
Moves via a one-way system with contraction of skeletal and smooth muscles.
What happens when there is obstruction in the lymphatic system?
It leads to edema, which is the accumulation of fluid in the tissues.
What are the three types of defenses in the immune system?
- First Line of Defense: Non-specific Immunity
- Second Line of Defense: Non-specific Immunity
- Third Line of Defense: Immune Specific or Adaptive Response
What are mechanical barriers in the first line of defense?
- Skin
- Mucous membranes
- Cilia hairs
What are chemical barriers in the first line of defense?
- Sweat
- Mucus
- Tears
- Saliva
- Stomach acid
What role do resident microorganisms play in immunity?
Normal flora that help prevent the growth of harmful pathogens.
What are the components of the second line of defense?
- Immune cells (e.g., Basophils, Phagocytes)
- Proteins
- Inflammation
- Fever
What triggers the inflammatory response?
Cytokines and histamines released when tissues are damaged or attacked.
What is phagocytosis?
The process by which phagocytes engulf and digest foreign cells.
What happens during a fever?
Core body temperature increases to kill pathogens and enhance cell metabolism.
What is the maximum temperature for a fever to avoid damaging host cells?
40 degrees Celsius.
What are antigens?
Surface markers on all cells that the body recognizes as self or non-self.
What is the role of Helper T-cells in the specific immune response?
Recognize pathogens and activate B-cells and Cytotoxic T-cells.
What do plasma cells produce?
Antibodies that deactivate pathogens.
What is the function of memory B-cells and memory T-cells?
Remain in the body to speed up the immune response if the same antigen reappears.
True or False: Suppressor T-cells stop the immune response when all foreign antigens have been destroyed.
True.
Fill in the blank: The first line of defense includes _______ barriers.
physical, chemical, and mechanical.
What are the two types of immunity?
- Cellular Immunity
- Antibody or Humoral Immunity
What do lymphocytes detect?
Presence of foreign antigens
Lymphocytes are essential for identifying threats to the immune system.
What specific proteins do lymphocytes produce?
Antibodies
Antibodies play a crucial role in the immune response.
How does an antibody operate?
Deactivation of a bacterium by an antibody
Antibodies neutralize pathogens and mark them for destruction.
What is the first line of defense in the immune system?
Non-specific Immunity
This includes physical, chemical, and mechanical barriers.
What role do Basophils play in the immune system?
Release Histamine
Histamine is involved in inflammatory responses.
What do Phagocytes do?
Engulf pathogens
Phagocytes are essential for clearing infections.
What type of cells patrol the lymph and blood looking for abnormal cells?
Natural killer cells
They can destroy infected or cancerous cells.
What is inflammation caused by?
Histamine
Inflammation is characterized by redness, warmth, swelling, pain, and discharge.
What does fever do in the immune response?
Triggers an increase in body temperature
This helps kill pathogens and reduces iron levels to inhibit reproduction.
What is the third line of defense in the immune system?
Specific Immunity
This targets specific pathogens for a tailored immune response.
What do T-lymphocytes initiate?
Cell-mediated immunity
T-lymphocytes are crucial for fighting infections at the cellular level.
What do B-lymphocytes initiate?
Antibody immunity
B-lymphocytes are responsible for producing antibodies.
What is acquired immunity?
A state of immunity developed after exposure to specific antigens
This allows for quicker response upon re-exposure.
What are the three types of acquired immunity?
- Naturally Occurring Immunity (NAI)
- Artificially Acquired Immunity (AAI)
- Passively Acquired Immunity (PAI)
Each type has different mechanisms of protection.
What is Naturally Occurring Immunity (NAI)?
Occurs when the body is exposed to infectious agents
This can happen through infections.
What is Artificially Acquired Immunity (AAI)?
Occurs when the body is exposed to weakened or killed infectious agents through vaccination
Vaccines help prepare the immune system for future infections.
What is Passively Acquired Immunity (PAI)?
Results when antibodies are introduced into the body
This can occur through breastfeeding or antibody treatments.
What do antibiotics do?
Kill or inhibit the growth of microorganisms
Antibiotics target bacteria specifically.
What is the function of Penicillin?
Inhibits cell wall synthesis in bacteria
This mechanism damages bacterial cells without harming human cells.
What is the most common antibody in the blood?
IgG
IgG can cross the placental membrane and provides passive immunity to the fetus.
What does IgM do?
Reacts with certain antigens, usually on first exposure
IgM is often the first antibody produced in response to an infection.
What is the role of IgA?
Protects mucosal surfaces from attachment of pathogens
Found in secretions like saliva and tears.
What is the function of IgE?
Involved in allergic reactions
IgE binds to mast cells, which release inflammatory substances.
Where is IgD typically found?
On B cells
IgD may be involved in B cell activation but is not released into the bloodstream.
